GM Service Manual Online
For 1990-2009 cars only

Body Control Module (BCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF

Battery Voltage Signal

BCM, Power Mode

Volts

12.6 Volts

Crank Request

BCM, Power Mode

Off, Accessory, Run, Crank Request

Off

Idle Boost Level

BCM, Power Mode

Numeric

0

Run/Crank Relay

BCM, Keyless/Remote Start Data

On, Off

On

Run/Crank Relay Command

BCM, Keyless/Remote Start Data

On, Off

On

L61 Powertrain Control Module (PCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF

Crank Request Signal

Engine Electrical, PCM

Yes/No

No

GEN F-Terminal Signal

Engine Electrical, PCM

%

0%

GEN L-Terminal Signal

Engine Electrical, PCM

No Voltage/Voltage

Voltage

Ignition 1 Signal

Engine Electrical, PCM

Volts

12.6 V

Starter Relay Command

Engine Electrical, PCM

On/Off

Off

TR Sw.

Automatic Transaxle, Data Display, PCM, Transmission Data

Park, Reverse, Neutral, Invalid, Drive 4, Drive 3

Park

LX9 Powertrain Control Module (PCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF

Crank Request Signal

Engine Electrical, PCM

Yes/No

No

Generator Lamp Command

Engine Electrical, PCM

Off/On

Off

GEN L-Terminal Signal Command

Engine Electrical, PCM

On/Off

Off

Ignition 1 Signal

Engine Electrical, PCM

Volts

12.6 Volts

Starter Relay Command

Engine Electrical, PCM

On/Off

Off

Starter Relay Circuit History

Engine Electrical, PCM

OK, Open, Short, Invalid State

OK

TR Sw.

Automatic Transaxle, Data Display, PCM, Transmission Data

Drive 1, Drive 2, Drive 3, Drive 4, Neutral, Reverse, Park, Invalid

Park

LZ9 Engine Control Module (ECM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF

GEN F-Terminal Signal

Engine Electrical, ECM

%

0 %

GEN L-Terminal Circuit Status

Engine Electrical, ECM

Incomplete, Short Gnd / Open, Short to B+, OK

OK

GEN L-Terminal Command

Engine Electrical, ECM

%

0 %

Ignition 1 Signal

Engine Electrical, ECM

Volts

12.6 Volts

Starter Relay Circuit Status

Engine Electrical, ECM

Incomplete, Short Gnd / Open, Short to B+, OK

OK

Starter Relay Command

Engine Electrical, ECM

On/Off

Off

LZ9 Transmission Control Module (TCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF

IMS

Automatic Transaxle, Data Display, TCM, Transmission Data

Drive 3, Drive 4\Drive 3, Park\Reverse, Reverse, Drive 3\Drive 2, Drive 2, Park, Invalid, Neutral\Drive 4, Drive 4, Neutral, Reverse\Neutral, Drive 1, Drive 2\Drive 1, Open

Park